1. Field of the Invention
The present invention relates to a power-driven ornithopter using an electric motor as a power source, and more specifically, to a power-driven ornithopter piloted by a remote controller wherein a takeoff and landing motion, a climbing and descending motion, and a turning motion of the ornithopter can be controlled using the remote controller.
2. Description of the Prior Art
An ornithopter still arouses persons"" curiosities due to its nature-friendly shape. There have been continuous attempts to develop the ornithopter as a leisure or toy aircraft that requires relatively lower flight stability.
Recent attempts to develop the ornithopter will be described below.
U.S. Pat. No. 4,729,748 (Mar. 8, 1988) issued to Gerard Van Ruymbeke discloses a flying toy. The flying toy includes a body, main wings and tail wings that have appearances similar to those of a body, wings and a tail of a bird; an elastic band; a wind-up assembly for twisting the elastic band; an activation assembly for activating flapping of the main wings, which are similar to flapping of the wings of the bird, by transferring force released when the twisted elastic band is untwisted; and a latching assembly for latching or locking the main wings when the elastic band is twisted. U.S. Pat. No. 5,163,861 (Nov. 17, 1992) issued to Gerard Van Ruymbeke discloses a wing-operated flying toy and a process for automatically locking the wings at the end of a flight. The flying toy of the ""861 patent is constructed such that a locking device, which is similar to the latching assembly of the toy of the ""748 patent, locks the main wings even when the toy flies while the elastic band is untwisted.
U.S. Pat. No. 4,749,149 (Jul. 7, 1988) issued to Peter Gruich discloses an ornithopter-type vehicle and methods of constructing and utilizing the same. The ornithopter-type vehicle is designed as an aircraft which is large enough to load persons thereinto. The ornithopter-type vehicle has main wings and a horizontal tail attached to its body in a manner similar to the fixed wing aircraft. An up motion of the flapping of the main wings that move between their higher and lower positions is established by elastic restoring force. A down motion of the flapping is established by power transferred from a power source through a hydraulic circuit. The ornithopter-type vehicle simultaneously obtains both the lift and thrust by the down motion of the main wings in a downward and rearward direction rather than a vertically downward direction from the higher position. The ornithopter-type vehicle is constructed such that its flight attitude is maintained in such a manner that a user controls the motion of the main wings and the position of the horizontal tail through operating levers.
U.S. Pat. No. 5,899,408 (May 4, 1999) issued to Kenneth R. Bowers, Jr. discloses an ornithopter. The ornithopter also has a main wing and a horizontal tail attached to its body in a manner similar to the fixed wing aircraft and employs a gasoline engine as a power source. The ornithopter is provided with flaps formed at the bottoms of the main wing so as to increase the lift obtainable from the flapping of the main wing.
Although such research results regarding the ornithopter have been proposed, there has been scarcely any commercialized power-driven ornithopter because of various factors.
The present inventor(s) has (have) invented an ornithopter including a power transmission mechanism which is lighter, simpler and more durable as compared with the conventional ornithopter, and an electric motor which can be simply operated and provide longer flight time as compared with its weight, which was filed on the same date of filing of the present application. The ornithopter includes a body, a main wing attached to an upper portion of a front section of the body, and tail wings attached to a rear section of the body. Both the electric motor and the power transmission mechanism are installed within a housing of the body. The power transmission mechanism includes a gear train for transmitting a rotational motion of the electric motor at a proper speed, and a connecting rod for converting the rotational motion into a swing motion of the main wing.
According to the ornithopter, a thrust is obtained from a reaction force to an action of pushing air toward the rear of the body by means of the flapping of the main wing. Further, vertical components of the thrust and drag obtained When a nose of the ornithopter is raised according to a vertical swing angle of the horizontal tail are utilized as a lift.
Such a power-driven ornithopter can fly for a considerably long time. Thus, if the ornithopter is left freely without any control thereof, the ornithopter may be flown far away to an extent that it is difficult to retrieve the ornithopter at a site where it has started to fly. Furthermore, the ornithopter is required to be controlled even for arousing interest in a person. However, any documents do not specifically describe the control or operation mechanism of the ornithopter.
An object of the present invention is to provide a power-driven ornithopter piloted by a remote controller wherein a takeoff and landing motion, a climbing and descending motion, and a turning motion of the ornithopter can be controlled using the remote controller.
Another object of the present invention is to provide a remote control system of a power-driven ornithopter wherein a flying speed of the ornithopter can be controlled by increasing or decreasing a thrust according to a flapping rate of a main wing and a flight altitude of the ornithopter can also be controlled by properly adjusting a vertical swing angle of a horizontal tail according to the flying speed.
An ornithopter of the present invention comprises a body, a main wing attached to an upper portion of a front section of the body, and a horizontal tail attached to a rear section of the body. Further, the ornithopter comprises an electric motor and a first servo motor for rotating by receiving electric power from a battery mounted to the body, a main power transmission mechanism for converting and transmitting the rotational motion of the electric motor into a swing motion of the main wing, a servo power transmission mechanism for adjusting a vertical swing angle of the horizontal tail as the servo motor rotates, and a controller for adjusting rotational direction and speed of the servo motor.
Preferably, the ornithopter further comprises an additional servo motor of which a rotating shaft is connected to a portion corresponding to a central axis of the horizontal tail, whereby a rotating angle of the horizontal tail can be adjusted as the additional servo motor rotates.
Preferably, the ornithopter further comprises a vertical tail disposed at an upper side of the horizontal tail. At this time, it is preferred that a second servo motor be connected to a vertical tail support for supporting the vertical tail so that a horizontal swing angle of the vertical tail can be adjusted by rotating the vertical tail support as the second servo motor rotates.
Further, the controller may control the rotational direction and speed of each of the servo motors by regulating driving power supplied from the battery to servo motor.
Furthermore, the controller may comprise a speed controller using a MOSFET (Metallic Oxide Semiconductor Field Effect Transistor).
It is also preferred that the controller be constructed to regulate driving power supplied to each of the servo motors in response to control signals received from a remote control transmitter.
It is more preferred that the controller be constructed to adjust a swing speed of the main wing by regulating the driving power supplied to the electric motor for actuating the main wing in response to the control signals received from the remote control transmitter.
Herein, if it is not specifically described, it should be understood that all the terms for designating the directions are used to refer to directions based on the ground in a state where the ornithopter of the present invention is placed on the ground with a normal attitude.